<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .box{
      width: 800px;
      height: 400px;
      background-color: pink;
      perspective: 100px;
    }

    .box .inner{
      width: 200px;
      height: 200px;
      font-size: 20px;
      line-height: 200px;
      text-align: center;
      color: #fff;
      background-color: #f00;
      transition: 1s;
    }

    .box:hover .inner {
      transform: rotateX(180deg);
    }
  </style>
</head>
<body>
  <h3>空间旋转</h3>
  <p>空间旋转是指盒子以空间内的任意直线为旋转轴而进行的旋转，这条旋转轴的位置由 x、y、z 三个矢量值决定。</p>
  <div class="box">
    <div class="inner">我在旋转</div>
  </div>
</body>
</html>